The application domain of the invention extends in the first place to the spectrometry of diffuse X rays or gamma rays, in particular the analysis of materials, but it comprises also other diffusion spectrometries. This type of spectrometry can be used in the study of materials, for instance the detection of explosives.
The diffusion spectrometry of X rays is based on exposing a material to incident X rays with energy equal to a few tens to a few hundreds keV. When they encounter the material on which they are projected, the X photons induce different types of interaction with the material: fluorescence or internal conversion (photoelectric effect during which the photon transfers all its energy to the material which returns it afterwards), inelastic diffusion, (or Compton effect which includes a change in the direction of the photon and a reduction of its energy), creation of positon-electron pairs (uniquely for X rays with very high energy not considered in the present invention), or Rayleigh diffusion (or elastic diffusion, a minority of the considered energies).